Abstract Vietnam is currently decentralizing its methadone maintenance therapy (MMT) dispensing network to its local commune health centers (CHC), which provides a window of opportunity to study decentralization of harm reduction and HIV-related healthcare services into community-based healthcare settings. Commune health workers (CHW) in Vietnam have widespread misconceptions about harm reduction and perceived significant challenges associated with treating people who use drugs. Intervention effort is needed to address these issues to ensure a smooth implementation of the decentralized service model. The proposed two-year study plans to design and pilot test an intervention to facilitate the delivery of decentralized MMT/HIV services via three phases in Phu Tho Province, Vietnam. In Phase 1, we will conduct task analysis with MMT clients and cross-functional analysis with service providers to identify the steps/tasks that are associated with most procedural delays, errors, redundancies, and/or unnecessary reworks. We will also evaluate each CHC?s capacity and readiness to deliver the MMT services. In Phase 2, under the framework of intervention mapping, a multidisciplinary working group will go through the six steps to design the intervention and develop its implementation and evaluation plan. The intervention, with a primary focus on process optimization, will be executed through a combination of in-person training and mobile phone application utilization. In Phase 3, we will pilot the intervention in six CHC-based MMT distribution sites. The six CHC will be randomized to either an intervention condition or a control condition. The intervention outcomes on CHW and MMT clients will be evaluated at baseline, 3-, and 6-months. The intervention will be revised and finalized based on acceptability/feasibility evaluation data, process evaluation data, and feedbacks from intervention facilitators and participants.